143840: How should zakaah on wealth belonging to orphans be paid?

I have some orphans under my care. I bought some shares in their name using my own capital, and when I sell the shares, I take back my capital and the profit remains in their account. Please note that some wealth has accumulated from these earnings for them, and I invest some of these earnings and some of that remains in their account, and one year has passed for some of the earnings.
My question is: How should zakaah be paid in this case, because they are minors and any zakaah is to be paid from their monthly income? Please note that their monthly income covers their needs.

Praise
be to Allaah.

Everyone who possesses wealth that reaches the minimum
threshold (nisaab) and one year has passed since he acquired it, is
obliged to pay zakaah on it, whether he is old or young, of sound mind or
otherwise.

No differentiation is made between orphans and others in this
case, because zakaah is what is due from wealth, as Allaah says
(interpretation of the meaning):

“Take Sadaqah (alms) from their wealth in order to purify
them and sanctify them with it”

[al-Tawbah 9:103].

In Fataawa al-Lajnah al-Daa’imah (14/293) it says: It
is obligatory for the guardian (wali) to pay the obligatory zakaah on the
wealth of minors if it reaches the nisaab and one year has passed since it
was acquired. End quote.

This has been discussed in detail in the answer to question
no. 75307.

Based on that:

1.
If the wealth of each of these
orphans has reached the nisaab as defined in sharee‘ah (the value of 595
grams of silver), then you have to pay zakaah on his behalf.

2.
With regard to the profits that
you put in their account, if it came from your capital then it is a gift
from you to them, and it comes under the same heading as wealth acquired
during the year. So you should work out a separate year for that, starting
from the date you gave it to them.

3.
With regard to the profits that
come from their own capital, they should not work out a separate year for
that; rather the year for them starts from the date the capital was acquired
and zakaah should be paid on (the profits) at the same time.

One of the duties of the wasiy (guardian) is to take care of
orphans placed under his care, look after them, protect their wealth and
invest it according to what is in their best interests according to
sharee‘ah. There is no doubt that what you are doing, using your money for
trading in shares and putting the profits in their account, is a good and
righteous deed for which you will be rewarded.